Abstract
Introduction: Fibrocytes are circulating precursors for fibroblasts. Their role in the pathogenesis of IPF is debated. Blood Fibrocytes are increased in patients with IPF, but there are no data concerning BAL. The aim of this study was to determine whether fibrocytes are present in the alveolar space and identify their prognostic value.
Methods: We detected and quantified fibrocytes by FACS (CD45+, Collagen1+) in BAL from 26 patients with IPF (3 exacerbations), 8 patients with Systemic Sclerosis and lung involvement, and 11 controls. BAL cells were cultured to isolate alveolar fibroblasts. MCP-1 and CXCL12 were measured in BAL fluid.
Results: Fibrocytes were not detected in controls, but were detected in 14/26 IPF (54%) and 4/8 SSc. Median% fibrocytes was 2.5% [0,4-19,7] in IPF, 3.0% [2.7-3.7] in SSc (NS). Fibroblasts were cultured from BAL in 12/26 IPF (46%), 5/8 SSc (65%) and 2 controls (P= 0,04). The detection of fibrocytes was not associated with demographics, delay from diagnosis, fibrosis HRCT score, or% survival but was associated with lower DLCO. Fibrocytes did not correlate with MCP-1 and CXCL12 BAL concentration and was not associated with the presence of fibroblasts in culture.
Conclusion: Fibrocytes are detected in BAL fluid in about half patients with IPF and SSc. Their prognostic significance is uncertain.
- © 2011 ERS